Apparatus and method for fluid injection

Abstract

Methods and apparatuses for metered injection of a fluid packet. A vessel containing a fluid is pressurized to a pressure less than or equal to a hold-off pressure. The fluid is subjected to an extraction force to form the fluid packet and extract the fluid packet from the vessel onto a surface.

1. A method for metered injection of a fluid packet, comprising:
 pressurizing a vessel containing a fluid to a pressure less than or equal to a hold-off pressure;  
 subjecting the fluid to an extraction force comprising dielectrophoresis to form the fluid packet and extract the fluid packet from the vessel onto a surface; and  
 removing the fluid packet from the surface through an exit port.  
 
     
     
       2. The method of  claim 1 , wherein the extraction force is produced by an electrode. 
     
     
       3. The method of  claim 2 , wherein the electrode is coupled to the surface. 
     
     
       4. The method of  claim 1 , wherein the extraction force is produced by an electrode array. 
     
     
       5. The method of  claim 1 , wherein the vessel comprises a flow-through injector. 
     
     
       6. The method of  claim 1 , wherein the pressure is between 65% and 85% of the holdoff pressure. 
     
     
       7. The method of  claim 6 , wherein the pressure is between 75% and 85% of the holdoff pressure. 
     
     
       8. The method of  claim 6 , wherein the size of the fluid packet is electronically controlled. 
     
     
       9. The method of  claim 1 , wherein there are two or more exit ports. 
     
     
       10. The method of  claim 1 , wherein the exit port is coupled to a conventional fluidics device. 
     
     
       11. The method of  claim 1 , further comprising the metered injection of two or more fluid packets from two or more pressurized vessels. 
     
     
       12. The method of  claim 11 , further comprising using a switching pump, wherein the switching pump switches the extraction force between a first fluid packet in a first pressurized vessel and a second fluid packet in a second pressurized vessel. 
     
     
       13. A method for metered injection of a fluid packet, comprising:
 pressurizing a vessel containing a first fluid to a pressure less than or equal to a hold off pressure, the first fluid comprising a first dielectric material;  
 energizing one or more electrodes coupled to a surface adjacent the vessel, the surface including a second fluid comprising a second dielectric material;  
 subjecting the first fluid to an extraction force comprising dielectrophoresis from the one or more electrodes to form the fluid packet and extract the fluid packet from the vessel onto a surface; and  
 removing the fluid packet from the surface through an exit port.  
 
     
     
       14. An apparatus for moving a fluid packet, the apparatus comprising:
 a vessel configured to contain a fluid;  
 a pressure manifold coupled to the vessel;  
 a pressure reservoir coupled to the manifold and configured to pressurize the vessel to a pressure less than or equal to a hold off pressure;  
 a device capable of generating a programmable extraction force, the extraction force comprising dielectrophoresis and being configured to form the fluid packet and extract the fluid packet from the vessel onto a surface;  
 an exit port coupled to the surface and configured to receive the fluid packet.  
 
     
     
       15. The apparatus of  claim 14 , wherein the exit port is hydrophilic. 
     
     
       16. The apparatus of  claim 14 , comprising a plurality of exit ports. 
     
     
       17. The apparatus of  claim 14 , further comprising a conventional fluidics device coupled to the exit port. 
     
     
       18. The apparatus of  claim 14 , wherein the vessel comprises a flow-through injector. 
     
     
       19. The apparatus of  claim 14 , wherein there are two or more pressurized vessels. 
     
     
       20. The apparatus of  claim 19 , further comprising using switching pump, wherein the switching pump is configured to switch the extraction force between a first fluid packet in a first pressurized vessel and a second fluid packet in a second pressurized vessel.